Tool shield



' `Figure 6 is a 'r Figure 5. f

United States Patent 2,893,005 TOOL SHIELD Elmer F. Pfalf, Mantua, and Robert W. Henning, Fairview Park, Ohio, assignors, by mesne assignments, to

Olin Mathieson Chemical Corporation, a corporation of Virginia Application May 10, 1956, Serial No. 584,054 12 Claims. (Cl. 144.5)

This invention relates to a tool shield and more particularly to a tool shield adapted to conform to various different configurations of work pieces against which it is abutted during operation of the tool.

In various types of power tools such as punching, riveting, or fastener driving tools, it is desirable to provide the tool with a shield which engages the work piece to prevent shattered particles of the work piece or ricocheting fasteners from being propelled through the air and causing possible injury to nearby personnel and material. Such a shield is normally of a generally cupshaped configuration with the working end of the tool projecting through the base of the cup and engaging the work piece, and with the walls of the cup adjacent the open end thereof also engaging the workpiece thereby providing a closed space around the working end of the tool. Such a shield is entirely adequate when the work piece is at, but should the work piece have protrusions such as ribs on the surface thereof the shield will not properly engage such a surface to provide a closed chamber for preventing the escape of any shattered particles of the work piece or ricocheting fasteners. Various special shields have been devised for engaging round posts, or other members having a particular shape. All such specially-designed shields have an obvious disadvantage in that a different shield must be used for different shaped -work pieces, resulting in a loss of time in changing shields.

It is, therefore, an object of this invention to provide a shield for use in conjunction with power tools such as explosively powered fastener driving tools wherein the shield is adapted to engage various shaped work pieces and provide a substantially closed space in conjunction with the work piece.

Another object of this invention is to provide such a shield which is adapted to automatically conform to the shape of various work pieces.

Another object of this invention is to provide such a shield for preventing the escape of shattered particles of the work piece or ricocheting fasteners or the like,

Additional objects and advantages will be apparent from the following description and drawings in which:

Figure l shows the muzzle end of an explosively powered fastener driving tool in the operative position and having attached thereto an embodiment of a shield adapted to conform to various configurations of a work piece;

Figure 2 is a sectional View taken on the line 2 2 of Figure 1;

Figure 3 `is a detailed perspective view of a spring which is part of the aforementioned embodiment;

Figure 4 is a sectional view taken on the line 4--4 of Figure l;

Figure 5 shows the tool of Figure l in the inoperative position, and another embodiment of a shield; and

sectional view taken on the line 6-6 in Shields of the type hereinafter described are suitable for use with various tools such as riveting, punching, or fastener-driving 'tools and will be described in conjunction with an explosively-powered fastener driving tool. lThe structure and functioning of arsuitable tool will be Y described insofar as it affects theshield. As shown` in ice Figure 2, a typical tool comprises a barrel 3 having a bore 5 through which a fastener 7 is driven. Telescopically received about the barrel is a tubular member or shield tube 9 to which is attached a shield 11 which is a cup-shaped member having the opposing side walls 31 and including an adjacent side wall cut-out portion occupied by a plurality of protean wall means comprising movable plates 33 adaptable for clearing any shape of workpiece entering into the cup-shaped shield between the spaced side walls 31.

Telescopically received about the tubular member 9 is a housing 13. A cap 15 having a bore 17 aligned with the barrel bore 5 is threaded onto the muzzle end 19 of the barrel 3. This cap is of greater diameter than the bore of the tubular member 9 and prevents removal of the tubular member 9 and shield 11 over the muzzle end 19 of the barrel. In Figure 2 the tool is shown in the operative ready-to-tlre position. A compression spring 21 engages a shoulder 23 provided by the upper wall of the shield 11 and a second shoulder 25 provided by an inwardly projecting portion of the housing 13, to urge the shield away from the housing. As illustrated in Figure 6, in the normal inoperative position of the tool, the inner surface 27 of the upper wall of the shield is forced against and retained by the cap 15 on the muzzle end of the barrel with the front or lower end of the housing 13 spaced from the outer wall of the tool shield. In order to fire the tool and drive the fastener 7 through the barrel bore 5, the housing 13 and barrel 3 must be pressed downwardly against the resistance of the spring 21 and toward the tool shield 11 to the position shown in Figure 2.

In Figure 1 the tool housing is shown in the operative position, the housing 13 having been forced against the shield 11. The shield 11 comprises an upper plate or base member 29 to which the shield tube 9 is attached and a pair of downwardly projecting side walls 31. Intermediate the side walls 31 adjacent opposite edges of the upper plate 29 are a plurality of plates 33 pivoted `together by a shaft 35 passing through the top ends of the plates and the side walls. The pivoted plates 33 are spaced as closely together as possible to permit pivotable movement therebetween. A reed-type spring 37,. shown in detail in Figure 3, is attached to the inner surface 27 of the upper plate 29 of the shield at each open end thereof and each reed 39 of the spring engages the inner edge 41 of one of the pivoted plates 33 to urge the plates to the position shown by kthe outer end plates 33 in Figure l. The top innerredge 43 of each plate 33is curved to permit the plate to swing inwardly and the outer portion of the top edge 45 of each plate is fiat and engages the inner surface 27 of the upper plate 29 of the shield to prevent outward pivotable movement of the plates. The lower end 47 of each plate is curved from the outer edge 49 thereof to the bottom of the inner edge 41 so that the plates will be forced inwardly against the resistance of the reed-type spring 37 when the shield is positioned on an irregularly-shaped work piece surface as T-shaped member 51. In Figure l the shieldpis in the operative position in engagement with the T-shaped member 51 and it will be noted that the pivoted plates 33 in engagement with the leg 53 of the T are inclined inwardly to a greater extent than the pivoted plates in engagement with the web 55 ofthe T and that the pivoted plates which are not in engagement with the work piece are parallel with the axis of the tool.

Figures 5 and 6 show another embodiment of a shield 57. As shown-here the tool housing 13 is in the inoperative position and spaced from the top wall or base member 59 of the shield. Opposite sides 61 of the shield are'cut out and a plurality of inter-engaging tongue and grooved sliding plates 63 are mounted on each of these 3, cut out walls. The sliding plates 63 are held in-position between a bar 65 projecting laterally outwardly from the sidesy 61 of the` shield,` the shield walls 61, and a pair of projections 67 on Veach sliding bar.` rlhus, as the shield is emplaced against' an irregularly shaped work piece 69, the sliding bars will conform to and engage the irregular surface of the work piece to` form a closed chamber within the shield to prevent escape of shattered portions of the work piece or ricocheting fasteners and the like. If this shield is to be used in emplacing a number of fasteners in identically shaped work pieces, the sliding bars 63 may be locked in place by means of locking bars 71 mounted on the upper wall 59 of the shield adjacent theZ bars 63. An eccentric cam 73v is pivotably mounted on the upper wall 59 of the shield intermediate the locking bars. The ca m is providedwith an arm 75 by means of which the ammay be rotatedY on its pivot 1 7 @A'sfgshqwn@ in Figure 5, are 1Q k ip g b a;s 7i are essed against they sliding plates V63 bythe `cam`73 which li` `been rotated to force'the'balrsjl apart1 One end of each locking bar. 71 is pivoted as at 79 to the upper wall 59 of the shield and the other end is slidably mounted on the upper wall 59 of the shield by a pin received in slot 72. The pivot 79 is spaced outwardly from the sliding bar 81 most removed from the cam. 73y so that when the cam forces the locking bar against the sliding plates the end of the locking bar adjacent the pivot will engage the adjacent sliding bar with sufficient force to maintain the plates in place. Withthe tool shown in the position of Figure 5 it is merely necessary to press the tool housing 13 toward the shield to place the assembly in the fastener driving position.

Although this invention has been described with particular reference to certain embodiments, details, and a particular operative environment, various modifications will be apparent to one skilled in the art. It is to be particularly noted that the pivoted or sliding plates may be attached to the shield body in many other manners, that the plates may be locked into position in other manners than by a cam and locking bars, and that shields of thisV type may be used with tools other than fastener driving tools. The invention, therefore, is not to be limited to such embodiments, details, or operative cnvironment except as set forth in the appended claims.

We claim:

1`. A shield to enclose an area of impact between an eaplosively driven element and an irregular surface .against Which'said element is driven from the barrel of apowderactuated tool, said shield comprising wall means having an end adapted to engage said surface, said wall meansfbeing oriticed opposite said end, a tube carried in [said orice for mounting said shieldon said tool wth said barrel passing into said orifice, and movable means 'in' said end of said wall means to permit said wall to conform to irregularities in the configuration of said surface against which said end of the wall is emplaced.

2. A safety shield for powder-actuated tools having a barrel adapted to explosively drive a penetrating fasten erinto a workpiece, comprising a shield box defined by an apertured plate for receiving the muzzle of the tool therethrough and a marginal side wall portion on said plate, theedge of which definesV an open face of said box 'adapted to be placed into engagement with the workpiece in` surrounding relationship with respect to the point where'the fastener is to be projected, said side wall havinga cutout portion, an articulated means mounted on saidbqx adjacentsaid cut-outportion as av protean part of said wallV to move intoconformity withY the-irregu- 'laritiesin the contour of said workpiece against which saidopen face of saidboxispositioned.

v3. A cup-shaped shield for -a powder-actuated tool having a barrel adapted to explosively drive a fastener into a workpiece, said shield having a closed end apervtured.for...reception of the.muzzle.of saidbarrel and having an open opposite end, a cut-out portion in a side 4 wall dening said open end, and means in said cut-out portion to conform to different configurations of work surfaces against which said open end of said shield is selectively positioned, said means comprsing a pluralty of pivoted members adapted to pivot into said cup.

4. A cup-shaped `shield for a powder-actuated tool having a barrel adapted to explosively drive a fastener into a workpiece, said shield having a closed end apertured for reception of the muzzle of said barrel and having an open opposite end, a cut-out portion in a side wall defining said open end, and means in said cut-out portion to conform to different configurations of work surfaces against which said open end of said shield is selectively positioned, said means comprising a plurality of members adapted to slide substantially perpendicularly to the plane of said open end of said cup". y

5, The shield of claim 4 and means tolock said sliding members in any givenposition.

6. A shieldfor a powder-actuated tool having a barrel adapted to explosively drive a fastener into the'irregular surface of a workpiece comprising a base member having an aperture for passage of the muzzle of said barrel into said shield into abutment with apoint on said surface and side Wall means on said base member projecting forwardly outwardly with respect to the plane of a surface of said base member to define a cup-like element having an open end, at least a portion of the open end of said wall being detined by a plurality of articulated means mounted on said shield whereby when the open end of said shield engages said irregular surface said articulated means may articulate in conformity with protrusions on the surface of said irregular surface adjacent to said articulated means therebyfacilitating engagement of the remainder of the open end of said shield with said irregular surface.

7. The shield of claim 6 wherein said articulated means comprises at least a plurality of contiguous members pivoted to said shield at a location away from the open end of said cup-like memberand adjacent the wall means of said cup-like member, the wall means of said cuplike member adjacent said pivoted members being cutout and said cut-out portion intersecting the open end of said cupllike member.

8. The shield of claim 7 and means tending to maintain said pivoted members in generally parallel alignment with the plane of said wall means adjacent said cut out portion thereof.

9. The shield of claim 8 wherein the last said means comprises a spring means tending to u'rge said pivoted vmembers in one direction and cooperating abutting surfaces on said pivoted members and another portion of said shield to limit the movement of said pivoted members in response to said springmeans.

10. The shield of claim 9 and means to attach said shield to said powder-actuated tool for propelling a fastener through said aperture, said means comprising a tubular member secured to said base member and projecting in a directionV substantially away from said wall, the axis of said tubular member and said aperture being in substantial alignment.

l1. The shield of claim 6 wherein said articulated means comprises at least a plurality of contiguous members mounted for sliding movement substantially in the plane of said wall means adjacent said base member and acut-outportion in said wall means adjacent said sliding members, said cut-out portion intersecting the open end of said cup-like member.

12. The shield of claim 1l and'mea'ns'to ix'said sliding lmembers in any given position with respectto the remainder of said means.

References Cited in the file of this patent UNITED STATES PATENTS 

